Rewrite ${\dfrac{7^{-10}}{7^{-12}}}$ in the form ${7^n}$.
Solution: ${ \dfrac{7^{-10}}{7^{-12}} = 7^{-10-(-12)}} $ ${ \hphantom{\dfrac{7^{-10}}{7^{-12}}} = 7^{2}} $